Ontario weather in March
In March, Ontario has daytime highs averaging 20 °C, nights around 8.5 °C, with 6.6 wet days. Figures are 1991–2020 climate normals.
- 20.3°C Average high
- 8.5°C Average low
- 6.6days Wet days
- 66mm Rainfall
- 12h Daylight
Daily temperatures through March
How March develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 March | 19.1 °C | 7.7 °C | 26 % |
| 11–20 March | 21.3 °C | 9.0 °C | 18 % |
| 21–31 March | 20.5 °C | 8.8 °C | 20 % |
- Average highs rise from 19.1 °C early in March to 20.5 °C by the end of it.
- Rain is most likely over days 1–10 of March (26 % of days) and least likely over days 11–20 (18 %).
What to expect
| Measure | Typical March | Share of the month |
|---|---|---|
| Days above 25 °C | 5.1 of 31 | 17 % |
| Days above 30 °C | 0.7 of 31 | 2 % |
| Days below 0 °C | 0.07 of 31 | 0 % |
| Days with more than 1 mm rain | 6.6 of 31 | 21 % |
Conditions in March
| Measure | Average |
|---|---|
| Mean temperature | 14 °C |
| Record high (1991–2020) | 33 °C |
| Record low (1991–2020) | -0.3 °C |
| Relative humidity | 69 % |
| Wind speed | 12 km/h |
| Cloud cover | 48 % |
Where Ontario ranks in March
| Ranking | Position | Value |
|---|---|---|
| Places with the best weather in North America in March | 42ndof 50 | 89/100 |
March compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 18.1 °C | 94 mm | 47 % |
| February | 18.5 °C | 101 mm | 49 % |
| March | 20.3 °C | 66 mm | 48 % |
| April | 22.8 °C | 26 mm | 40 % |
| May | 25.3 °C | 12 mm | 35 % |
See all twelve months for Ontario
- March is the 9th warmest month here.
- It is the 10th driest month of the year.
- It ranks 11th for least cloud cover.
- Days last about 12 hours from sunrise to sunset.
- It rains on 6.6 of 31 days — 21 % of the month.
- Nights are about 12 °C cooler than the middle of the day.
- The hottest March day on record since 1991 reached 33 °C, 12 °C above the usual daytime high.
Nearby destinations in March
| Destination | Avg high | Wet days | Sea |
|---|---|---|---|
| Ontario | 20 °C | 6.6 | – |
| Pomona | 20 °C | 7 | – |
| Fontana | 20 °C | 7 | – |
| Corona | 21 °C | 7 | – |
| Riverside | 21 °C | 7 | – |
| San Bernardino | 20 °C | 6 | – |
| Anaheim | 20 °C | 5 | 15 |
QuestionsMarch in Ontario, answered
How warm is Ontario in March?
Daily highs average 20 °C and nights fall to about 8.5 °C, a spread of 12 °C between afternoon and dawn. That makes March the 9th warmest month of the year here.
Does it rain much in Ontario in March?
March averages 66 mm of rain, spread over about 7 of the 31 days — 21 % of the month. Cloud cover averages 48 % of the sky.
How long are the days in March?
Ontario averages 12 hours between sunrise and sunset in March. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.